1. Field of the Invention
This present invention relates to a semiconductor substrate and, more particularly, to a pixel array substrate.
2. Description of Related Art
With growth of the society, every type of display has been developed for using in the mobile phone, notebook computer, digital camera and personal digital assist. Further, both liquid crystal display (LCD) and organic light-emit diode (OLED) are popular for everyone due to some advantages of themselves such as small size, low weight, and power saving. During manufacturing period of liquid crystal display or organic light-emit diode, the pixel array substrate is essential for the semiconductor process. By adjusting every pixel color displayed on the pixel array substrate, the display device can generate the image relative to the adjusting step.
FIG. 1 is an upper view of a conventional pixel array substrate. Referring to FIG. 1, the conventional pixel array substrate 100 comprises a substrate (not shown in the figure), a plurality of scan lines 110 disposed on the substrate, a plurality of data lines 120, a plurality of thin film transistor 130, a plurality of pixel electrodes 140 and a repair line 150, wherein each of the scan lines 110 respectively crosses with the data lines 120 for defining a plurality of pixel field (not shown in figure), and the repair line 150 locates around the plurality of the pixel fields. Therefore, each of the scan lines 110 aligns in a row and each of the data line 120 arranges in a line, and every pixel field comprises the thin film transistor 130 and the pixel electrode 140.
The thin film transistor 130, located near the intersection of the scan line 110 and the data line 120, electrically connects to the scan line 110, the data line 120 and the pixel electrode 140. In addition, the thin film transistor 130 receives the scan signal transmitted by the scan line 110 to determine a power-on/power-off status. While the thin film transistor 130 maintains the power-on status, the pixel electrode 140 can receive the data signal transmitted by the data line 120 through the thin film transistor 130 for adjusting the color of pixel.
During manufacturing process of the pixel array substrate 100, when one of the date lines 120 is broken 122, two ends of the broken data line 120 can be welded to the repair line 150 by using laser welding for forming two welding portions 124, and therefore, a signal can be transmitted through the repair line 150. Because the repair line 150 is too long, the conventional pixel array substrate may cause an RC delay. In addition, a repair line 150 only can repair a broken data line 120, thus if the quantity of the broken data lines 120 exceeds the number of the repair lines, the pixel array substrate 100 cannot be repaired.
FIG. 2A is an upper view of another conventional pixel array substrate. FIG. 2B is a cross-sectional view of pixel array substrate of FIG. 2A in the direction AA′. Referring to FIGS. 2A and 2B, the conventional pixel array substrate 200 comprises a substrate 210, a plurality of scan lines 220 disposed on the substrate 210, a plurality of data lines 230, a plurality of thin film transistor 240, a plurality of pixel electrodes 250 and a plurality of patterned floating lines 260, wherein each of the patterned floating lines 260 is disposed under the plurality of data lines 230 and overlapped with some data lines 230. In addition, a first insulation layer 10 is disposed between the patterned floating lines 260 and the data lines 230; a second insulation layer 20 is disposed above the data lines 230; a semiconductor layer 50 is disposed above the gate (not marked) of the thin film transistor 240.
FIG. 2C is a schematic view according to FIG. 2A, wherein the data line of the pixel array substrate is broken. FIG. 2D is a cross-sectional view of the arrangement according FIG. 2A in the direction AA′, wherein the data line 230 of the pixel array substrate is broken. Referring to FIGS. 2C and 2D, when the data line 230 is broken 232, two ends of the broken data line 230 can be welded to the patterned floating line 260 by using laser welding process for forming two welding portions 234 so as to repair the broken circuit of the data line 230.
Because the patterned floating line 260 and the scan line 220 are disposed in the same layer, the patterned floating line 260 cannot be disposed on the intersection of the data line 230 and the scan line 220. When the data line 230 is broken in the intersection of the data line 230 and the scan line 220, this conventional pixel array substrate 200 is unable to repair the broken data line 230.
FIG. 2E is a schematic view according to FIG. 2A, wherein the thin film transistor is broken. FIG. 2F is a cross-sectional view of the arrangement according FIG. 2E in the direction ZZ′. Referring to FIG. 2E and FIG. 2F, when the thin film transistor 240a is broken, for example, short circuit occurs between the gate 242a, the source 244a, and the drain 246a. Generally, by using laser cutting process to disconnect a wire connected with the drain 246a and the pixel electrode 250 can repair the pixel to become dark state.
In general, two adjacent pixel fields of the pixel array substrate 200 may substantially display the same color. When the pixel field relative to the thin film transistor 240 is in the dark state, the pixel field adjacent to the thin film transistor 240 is still in a normal display state. Accordingly, the user can be easy to discover the dead point of the pixel array substrate 200 and thus the display quality of display device is decreased.
FIG. 2G is a schematic view of another conventional pixel array substrate, wherein the data line 230 of the conventional pixel array substrate 200a is broken 232. Referring to FIG. 2G, the pixel array substrate 200a of FIG. 2G is similar to the pixel array substrate 200 of FIG. 2C, wherein the pixel array substrate 200a further comprises two light-shielding layers 260a disposed on the two sides of the data line 230, and the data line 230 further comprises a plurality of protruding portions 236 partially overlapped with light-shielding layers 260a. 
When the data line 230 is broken 232, the protruding portion 236 disposed on the two ends of the broken data line 232 can be welded to the light-shielding layer 260 by using laser welding process for forming a plurality of welding portions 234a capable of repairing the broken data line 230. Because both of the light-shielding layer 260a and the scan line 220 are disposed at the same layer, the light-shielding layer 260a cannot be disposed at the intersection of the data line 230 and the scan line 220. When the data line 230 is broken 232 in the intersection of the scan line 220 and the data line 230, this conventional pixel array substrate 200a cannot be repaired.
FIG. 2H is a schematic view of another conventional pixel array substrate 200b, wherein the data line 230 is broken 232. Referring to FIG. 2H, the pixel array substrate 200b of FIG. 2H is similar to the pixel array substrate 200 of FIG. 2C, wherein the pixel electrode 250b of the pixel array substrate 200b is partially overlapped with the data line 230. When the data line 230 is broken 232, the broken data line 232 can be welded to the pixel electrode 250b for forming two welding portions 234b capable of repairing the broken circuit status.
In summary, the dead point also can be found on the pixel array substrate by using the aforementioned method, and it's still not a better method to resolve the aforementioned question.